1. Field of Invention
This invention generally pertains to the protection of the weakest elements found in conventional padlock applications, and in particular to U-shaped shackle padlocks used in conjunction with the hasps or staples of typical attachment devices.
2. Description of Prior Art
The most commonly used padlocks and attachment devices such as hasps and staples are typical loose fitting and of "U" shape. This assures ease of use, flexibility, and minimal cost. Unfortunately these configurations provide ease of forced attack using bolt cutters, prying tools and similar methods. Many attempts have been made to protect these vulnerable elements such as can be seen in U.S. Pat. Nos. 676,001 (Jarvis), 1,220,941 (Bowers), 1,662,612 (Junkunc), and 3,572,064 (Berry et al). Other arrangements can be seen in the following:
U.S. Pat. No. 3,736,016 (Garvey et al) PA1 U.S. Pat. No. 3,751,948 (Klein) PA1 U.S. Pat. No. 3,916,654 (Mudge) PA1 U.S. Pat. No. 4,380,160 (Hoffman) PA1 U.S. Pat. No. 4,506,528 (Eberly) PA1 U.S. Pat. No. 4,774,823 (Callison) PA1 U.S. Pat. No. 4,781,043 (Loeffler) PA1 U.S. Pat. No. 4,843,845 (Poe) PA1 U.S. Pat. No. 2,584,575 (Goldwasser)
The common disadvantage reflected in the Prior Art is the limited use or restricted applications of the devices and the expensive construction required.